My youngest daughter had her princess experience back in 2013. My daughter is bi-racial but her hair is extremely long and the texture is more caucasian then anything else but the fairy godmother still had the most difficult time getting the bun done. She kept putting her hair up and taking it down and putting it up and taking back down. This happened at least 4 or 5 times, so much so that my oldest was like "mum do you think you should step in and just do Lizzybeth's hair yourself?". I told her no that there could be a number of reasons as to why she was having a difficult time with the bun, maybe it was the length of my daughter's hair (it's at her waist), texture (it does have a slight curl to it), maybe she was new and was nervous or maybe she wanted to make sure it was just right and looked it's best. Either way the amount of time she spent on it was more than most other fairy godmothers. Once it was done it did look very nice and we all were pleased so I never complained, I just felt bad because I thought of the other families who were still waiting to have their experience. The donut bun may be a way of doing the bun quicker therefore speeding up the entire process and being able to schedule more appointments.
In 2015 my daughter did the Pirate Makeover where she was a Mermaid Princess and the cast member was a Hispanic woman who mentioned that my daughter had hair similar to her own daughter's hair and so I think she had more experience and was able to quickly do her hair and move on to the makeup and other things. This year my daughter is going back to the Pirate Experience since she will officially be 13 for this trip and is no longer eligible for the princess make over at BBB and she is doing the Pirate Empress option. I'm not sure what that hairstyle is so I'll look on
Youtube to see if there are any examples.